Telephone system



NGV. 12-, 1940. WQCHINGER 2,221,660

TELEPHONE SYSTEM Filed Feb. 17, 1937 INVENTOR. EDUA RD WOCH/A/GEP ATTORNEY.

Patented Nov. 12, 1940 UNITED STATES PATENT OFFICE TELEPHONE SYSTEM Application February 17, 1937, Serial No. 126,131

. In Germany March 5, 1936 17 Claims.

tion from the moment of its initiation.

By call registering in this application is meant the registration or locking in of a call in an automatic switch.

In contradistinction to arrangements in which call registering is initiated by operating a magneto and is only released when the call has been switched through to succeeding devices or after an operator has entered the call, in the present arrangement the initiation of the registering is 20 similarly efi'ected by direct current but the registering can be suppressed by the calling station at any time as soon as the call has been initiated.

This is achieved in that a call receiving relay operated by an induced impulse in a particular direction, when the calling subscriber carries out the necessary switching measure for initiating a call, is deenergized by an induced impulse in the opp site direction when the calling subscriber abandons the setting up of the call.

The arrangement according tothe invention enables an efficient system to be produced by using switching elements of normal construction which fulfill the conditions imposed by a modern system.

The device for generating induced impulses enables the induced impulses following the operation of the dial switch to be transmitted without the transmission of induced impulses in oppo-' 40 site directions when initiating and abandoning a call being disturbed.

In the drawing an embodiment of the invention is represented to which embodiment the in-- vention is, however, not limited. Tn represents a subscribers station at which a call maybe initiated by removing the telephone receiver. l-lu represents the contacts operated by the switchhook, these contacts being switched over when the receiver is removed. H represents a device which is provided at the station for producing an induced impulse. A considerable range of impulses can be produced so that it can be used even when the connecting lines are in bad con-, dition.

551 When the subscriber at station Tn takes up his receiver the switch-hook contacts I-lul and Hu2 are switched over. By the switching over of contact Hui the speech repeater G and the telephone receiver F are connected to the line while the bell S is disconnected. The switching over of contact HuZ establishes the following circuit: negative pole of battery B, switch-hook contact HuZ, contact nsa which is switched over only when the dial plate is operated, relay K, contact 28 and positive pole of battery" B Relay K energizes and operates contacts 3k, 4k, and 57c. Winding of the transformer Tr is connected to the batter B by contact 4k. An induced impulse produced in winding II by the completion of this circuit is, however, not transmitted over the connecting line La since contact 5k closes later than contact 42b. The switching over of contact 370 operates relay S. This energizes in the following circuit: positive pole of battery B, relay S, contact 3k, switch-hook contact I-IuZ, negative pole v of battery B. Contact is opens the circuit over winding I of the transformer generating an impulse which passes over Winding II of the transformer Tr, contact 570, lead La, winding I of call relay R and contact 8t to earth at E2. Relay R is caused to energize by this impulse and switches over its contacts 61' and 11'. The following looking circuit is established for Winding II of relay R: earth, battery, winding II of relay R, contacts 61' and 9t, starting relay An and earth. Contact 1r characterizes the calling line on wiper so of the call finder AS. Relay An causes the free call finder to be started up in known manner.

After relay S has energized in the device I-I relay K is caused to deenergize through the switching over of contact Is since it is short-circuited by the following circuit: contact ls, relay K, contact 'nsa, switch-hook contact H102, contact ls. Relay K on releasing restores contacts 31c, 67c, and 576 to normal. Relay S is held energized in the following circuit: positive, pole of battery B, relay S, resistance Wz', contact ls, negative pole of battery B.

If new the calling subscriber abandons the call before the call finder AS is switched through, then when the receiver is replaced an induced impulse is transmitted in the opposite sense to the induced impulse previously transmitted by the device H in that when the switch-hook contacts are restored to normal the following circuit is thereby established: positive pole of battery B, contact 2s switch-hook contact HuZ, contact nsa, relay K, contact ls, negative pole of battery B. In this circuit relay K energizes. Contact 570 connects winding II of the transformer Tr to the lead La. Contact 3k short-circuits relay S in the following circuit: positive pole of battery B, relay S, contact 310, switch-hook contact Hu2, contact 25, positive pole of battery 13. Relay S 5 releases. The energizing circuit provided for winding I of transformer Tr is closed at contact Is. This energizing of winding I of transformer Tr ffects the transmission of an induced impulse to winding I of relay R. Since this impulse is produced by the closing of the circuit for winding I of transformer Tr it is in the opposite direction to the impulse which was transmitted when the call was initiated by the opening of the circuit for winding I offtransformer Tr. Relay R is accordingly deenergized by being de-magnetized. Contact 61' is opened so that the registering circuit passing over winding II of relay R is disconnected. The arrangement shown is now in the normal condition.

It should be mentioned that subscriber Tn can also be connected to the exchange device over two leads. In this case the connection to earth at points El and E2 must be disconnected and these points connected by a line.

The device H for producing induced impulses is also adapted for transmitting numerical inipulses. When the call has been initiated the testing relay P associated with the call finder energizes in the known way. Relay T thereupon also energizes and opens contacts 8t and 9t. Contact Hit is closed and maintains the testing circuit. An impulse receiving device is connected up in any desired manner (not shown) and is influenced over wipers sa and sb of the call finder. The calling subscriber receives a signal from the public exchange.

As already described when the call was initiated winding I of relay R was energized by an impulse produced by breaking the circuit for the transformer Tr. Relay S was energized. When now the subscriber at station Tn operates his dial switch contact nsa is closed. Relay K is energized over the positive pole of battery B, contacts 2s and ma, relay K, contact Is and the negative pole of battery B. Relay K operates its contacts. No impulse is transmitted since relay S is energized and accordingly contact I s is operated. As the dial plate runs back contact nsa remains closed while contact nsi is inter-- mittently operated. On account ofthe closing of contact nsi the following circuit is established for winding I of transformer Tr: positive pole of battery B, winding I of transformer Tr, contact nsz', switch-hook contact I-llu2, negative pole of battery B. An induced impulse isaccordingly transmitted and is followed on the opening of contact nsi by an induced impulse in the opposite direction. The latter induced impulse I transmitted on dialling is accordingly an impulse which is produced by breaking the circuit for the transformer T1 so that if the call is abandoned by replacing the receiver at the station Tn another closing impulse is produced in the manner already described. This impulse can be used for releasing the call in any known manner. After the transmission of this closing impulse by the deenergizing of relay S relay K also releases. Since contact 5k opens before contact Ms no impulse is transmitted when relay K releases.

What is claimed is:'

1. In a telephone system, a line, a telephone substation thereon, means for extending. con

. nections from'said line, means at the substation for setting up a calling condition in the first means by transmitting a single impulse of one polarity responsive to the removal of the receiver from the hook switch at the substation, and means for transmitting a single impulse of another polarity to remove the calling condi- 5 tion responsive to the replacement of the receiver.

2. In a telephone system, a line having a substation thereon, a local circuit at the substation inductively associated with said line, call ex- 10 tending devices for extending calls from the line, means responsive to an operation at a calling substation for originating an impulse in said local circuit to cause a single induced impulse to be transmitted over the line to said ex 15 tending devices to initiate the extension of a call from the line, and means responsive to another operation at the calling substation for originating an impulse in said local circuit to cause a single induced impulse to be transmitted 20 over the line to said extending devices to terminate a call.

3. A telephone system as claimed in claim 2 in which the two induced impulses are in opposite directions. 25

' 4. In a telephone system, a line, a circuit associated therewith, a relay connected to the line and controlled thereover to extend connections therefrom, means for transmitting over said line an impulse induced therein from said circuit to 30 operate said relay to initiate the extension of a connection, meansfor disconnecting said relay from the line responsive to the extension of said connection, and means for transmitting over said .line a second impulse induced therein from 35 said circuit to the relay to deenergize it before the extension has been made.

5. In a telephone system, a line, a circuit inductively associated therewith, means for extending connections from said line, means for 40 controlling said circuit to cause a single induced impulse to be transmitted over the line to initiate a call and a single impulse induced in the opposite direction to be transmitted to release an initiated call, and means responsive to the 45 operation of the calling device on said line for transmitting induced impulses over the line to further extend the connection after initiation and before release.

6. In a telephone system, a line, a circuit as- 5 sociated therewith, an automatic switch, a line relay for the line, means for transmitting over said line an impulse induced therein from said circuit to energize said relay to initiate the operation of said switch, means for maintaining said re- 55 lay energized responsive to said energization of same by the induced impulse, means for transmitting another induced impulse to the relay to deenergize it before the connection is extended, and means for transmitting other in- 0 duced impulses to complete the extension of a connection from the line if the relay is not deenergized before the connection is extended.

7. In a signalling system, a signalling station and a line circuit therefor, a local circuit at said 65 station, a source of direct current for said local circuit, means at said station for controlling said source to cause the amount of current flowing in said local circuit to increase and to decrease, and means for inductively associating said 10- 70 cal circuit with said line circuit only while the flow of current in said local circuit is constant or increasing, thereby to induce signalling current inbut one direction in the line circuit.

8. In a signalling system, a signalling station 73- and a line circuit therefor, a local circuit at said station, a source of direct current for said local circuit, means at said station for controlling said source to cause the amount of current flowing in said local circuit to increase and to decrease, and means for inductively associating said local circuit with said line circuit only while the flow of current in said local circuit is constant or decreasing, thereby to induce signalling current in but one direction in the line circuit.

9. In a signalling system, a signalling station and a line circuit therefor, a local circuit at said station, means for causing impulses of direct current to flow in said local circuit, and means for inductively associating said local circuit with said line circuit, said last means at times effective only while the current in the local circuit is constant or increasing, at other times effective only while the current in the local circuit is constant 30 or decreasing, and at still other times effective while the current in said local circuit is constant, increasing or decreasing, whereby signalling current induced in the line circuit is at said times in one direction, at said other times in the opposite direction, and at said still other times in both directions.

10. In a telephone system, a subscribers station and a line therefor, a local circuit at said substation, means at said substation operable either to initiate or to terminate a call, means for causing an impulse of direct current to flow over said circuit responsive to an operation of said last means either to initiate or to terminate a call, and means for inductively associating said circuit with the line, either only during the growth of current in said circuit upon the initiation of said impulse or only during the decay of current in said circuit upon the termination of said impulse in dependence upon whether said impulse is responsive to the initiation of a call or to the termination of a call, whereby current is induced in the line in a distinctive direction in dependence upon whether said first means is operated to initiate or to terminate a call.

11. In a signalling system, a signalling station and a line therefor, an electromagnetic responding device to be controlled over said line, a local circuit at the station, means for causing an impulse of direct current to flow in said circuit, and

means for inductively associating said circuit with the line, said last means at times rendered ineffective during the growth of current in said circuit upon the initiation of said impulse and rendered effective during the decay of current in said circuit upon the termination of said impulse thereby to transmit current induced in one direce tion over the line to operate said device in one way, said last means at times rendered elfective during the growth of current in said circuit upon 0 initiation of said impulse and ineffective during the decay of current in said circuit upon the termination of said impulse thereby to transmit current induced in another direction over the line to operate said device in a different way.

5 12. In a system such as claimed in claim 11, means for extending connections from said line, wherein said device is effective to initiate the extension of a connection from said line by said last means or to terminate the extension of a 70 connection from said line by said last means in dependence upon which of said ways said device is operated.

13. In combination, a transformer, a source of direct current for the primary winding of said transformer, means for controlling said source to cause the amount of current flowing through said primary winding to increase and to decrease, and means controlled by said last means for rendering the secondary winding of the transformer effective while the current in the primary Winding is increasing and ineffective while the current in the primary winding is decreasing, whereby current is induced in but one direction in said secondary winding.

14. In combination, a transformer, a source of direct current for the primary winding of said transformer, means for controlling said source to cause the amount of current flowing through said primary winding to increase and to decrease, and means controlled by said last means for rendering the secondary winding of the transformer ineffective while the current in the primary winding is increasing and effective While the current in the primary winding is decreasing, whereby current is induced in but one direction in said secondary winding.

15. In a signalling system, a signalling station and a line therefor, a transformer at said station having a secondary winding associated with said line, a source of current for the primary winding of the transformer, and means at said station for controlling said source to cause the amount of current flowing through said primary winding to increase and to decrease, said secondary winding connected to said line while the current in the primary Winding is increasing and disconnected therefrom while the current in the primary winding is decreasing, whereby induced signalling current is transmitted over the line in but one direction.

16. In a signalling system, a signalling station and a line therefor, a transformer at said station having a secondary winding associated with said line, a source of current for the primary winding of the transformer, and means at said station for controlling said source to cause the amount of current flowing through said primary winding to increase and to decrease, said secondary winding disconnected from said line while the current in the primary winding is increasing and connected thereto while the current in the primary winding is decreasing, whereby induced signalling current is transmitted over the line in but one direction.

17. In a signalling system, a signalling station and a line therefor, a transformer at said station having a secondary winding associated with said line, means for at times causing an impulse of direct current to flow through the primary winding of the transformer thereby to cause induced signalling current to flow in one direction through the secondary winding of the transformer and over said line, and means for at other times causing an impulse of direct current to flow through the primary winding in the same direc: tion as said first mentioned impulse of direct current thereby to cause induced signalling current to flow through the secondary winding of the transformer and over said line in a direction different from that in which said first induced current flowed.

EDUARD WOCHINGER. 

